GB559145A - Improvements relating to fastening devices - Google Patents

Abstract

559,145. Locking screws &c. SUMMERS, J. M. July 24 1942, No. 10406. Convention date, Nov. 7, 1941. [Classes 44 and 89 (i)] [Also in Group XXII] Members such as sheets forming parts of aeroplanes are connected by screw fastenings having a locking device integral with one of the parts and released automatically on application of the box spanner or other rotating tool. A sodket 21 is secured in a hole in one of the sheets 13 and an elongated socket 16 is secured in the sheet 12. A headed stud 27 is mounted in the socket 21 and carries a sleeve 41 with a two start thread engaged by nut segments 19, 20 on the socket 16. The sleeve 41 is secured in the hollow shank 26 by riveting over at 44 further riveting at 44' securing a disc 37 that confines a spring 29 engaging a crossbar 32 engaging slots in the shank in the sleeve 41 and in the underside of the socket 21 thus locking the screw from rotation. Then the driver 36 is inserted in the recess in the head of the stud to effect rotation the point engages a recess 31 in the crossbar 32 depressing it to clear the slots in the socket. A projection 33 on the crossbar is engaged by the spring to keep the crossbar central. The sockets are each formed with one flange to engage the sheet and with an annular rib such as 18 or 23 which is stamped down into the countersink or counterbore at the other side of the sheet. In a modification the stud is formed with a polygonal extension 67 bearing a box spanner that depresses the crossbar by means of a central stud 68 headed at 69. In a further modification the head of the shank has a polygonal hole to receive a headed polygonal member fitted with cross wings for hand manipulation the polygonal member being first depressed axially to release the crossbar.